Re: [take13 1/3] kevent: Core files.

[Andrew Morton]

On Fri, 25 Aug 2006 10:32:38 +0400
Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:

> On Thu, Aug 24, 2006 at 11:20:24PM -0700, Andrew Morton (akpm@xxxxxxxx) wrote:
> > On Fri, 25 Aug 2006 09:48:15 +0400
> > Evgeniy Polyakov <johnpol@xxxxxxxxxxx> wrote:
> > 
> > > kmalloc is really slow actually - it always shows somewhere on top 
> > > in profiles and brings noticeble overhead
> > 
> > It shouldn't.  Please describe the workload and send the profiles.
> 
> epoll based trivial server (accept + sendfile for the same file, about
> 4k), httperf with big amount of simulateneous connections. 3c59x NIC 
> (with e1000 there were no ioreads and netif_rx).
> __alloc_skb calls kmem_cache_alloc() and ___kmalloc().
> 
> 16158     1.3681  ioread16
> 8073      0.6835  ioread32
> 3485      0.2951  irq_entries_start
> 3018      0.2555  _spin_lock
> 2103      0.1781  tcp_v4_rcv
> 1503      0.1273  sysenter_past_esp
> 1492      0.1263  netif_rx
> 1459      0.1235  skb_copy_bits
> 1422      0.1204  _spin_lock_irqsave
> 1145      0.0969  ip_route_input
> 983       0.0832  kmem_cache_free
> 964       0.0816  __alloc_skb
> 926       0.0784  common_interrupt
> 891       0.0754  __do_IRQ
> 846       0.0716  _read_lock
> 826       0.0699  __netif_rx_schedule
> 806       0.0682  __kmalloc
> 767       0.0649  do_tcp_sendpages
> 747       0.0632  __copy_to_user_ll
> 744       0.0630  pskb_expand_head
> 

That doesn't look too bad.

What's that as a percentage of total user+system time?
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